Is acupuncture beneficial in the treatment of Bell's palsy? Best Evidence Topic (BET)

This Best Evidence Topic (BET) review investigated whether acupuncture offers benefits in the treatment of Bell's palsy, a common form of peripheral facial paralysis. The study was prompted by a clinical scenario in which a patient with Bell's palsy asked about the use of acupuncture, having obtained relief from this treatment for low back pain in the past. The search analyzed 43 articles identified in MEDLINE (1948-2012), of which three represented the best available evidence: two systematic reviews and one randomized clinical trial. The first review, conducted by Chen et al.

(2010), was a Cochrane review that analyzed six randomized clinical trials involving 537 patients. This review compared acupuncture with drug treatment (mainly steroids and B vitamins) and other interventions such as massage and electrode application. Four studies directly compared acupuncture with drugs, showing a significantly higher cure rate with acupuncture (p < 0.05). However, the authors expressed concern about the high risk of bias in the studies, mainly due to lack of clarity in randomization and absence of blinding.

Heterogeneity in interventions, outcome measures, and treatment duration precluded meta-analysis. The second relevant study was a clinical trial by Ahn et al. (2011) that compared traditional acupuncture versus combined acupuncture (traditional + auricular) in 49 patients with retroauricular pain, including 10 with Bell's palsy. The study showed a significant reduction in the visual analog pain scale of 2.5 ± 1.52 units after six sessions (p = 0.018).

However, the study had important limitations: a high dropout rate (36.7%), undescribed randomization method, absence of a placebo group, and subjective criteria for treatment duration. The third piece of evidence was a systematic review with meta-analysis by Kim et al. (2012) that included eight randomized clinical trials with 463 patients. This analysis showed a relative risk of 1.11 favoring acupuncture combined with drugs versus drugs alone (95% CI 1.05-1.17, p = 0.001) and a relative risk of 1.07 favoring acupuncture versus drugs (95% CI 1.02-1.13, p = 0.006).

Despite the statistically significant results, the authors cautioned about the methodological heterogeneity of the studies and the high risk of bias, questioning the appropriateness of pooling the data for meta-analysis. The clinical implications of this review are cautious. Although some data suggest a potential benefit of acupuncture, the methodological quality of the available studies is insufficient to establish firm recommendations. All analyzed studies had significant limitations, including problems with randomization, lack of blinding, heterogeneity in interventions and drugs used, and lack of standardization in outcome measures.

The authors conclude that, until well-designed trials can clearly demonstrate a role for acupuncture in Bell's palsy, its efficacy should be considered unproven. They recommend that patients be informed about the limited quality of the available evidence, which may be misleading, and suggest that future studies be randomized, adequately controlled, clearly reported, and blinded when possible, using objective measures of facial nerve function.